/*********************************************************************************
This code is provided for internal research and development purposes by Huawei solely,
in accordance with the terms and conditions of the research collaboration agreement of May 7, 2020.
Any further use for commercial purposes is subject to a written agreement.
 *  OKVIS - Open Keyframe-based Visual-Inertial SLAM
 *  Copyright (c) 2015, Autonomous Systems Lab / ETH Zurich
 *  Copyright (c) 2016, ETH Zurich, Wyss Zurich, Zurich Eye
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 * 
 *   * Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *   * Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation
 *     and/or other materials provided with the distribution.
 *   * Neither the name of Autonomous Systems Lab / ETH Zurich nor the names of
 *     its contributors may be used to endorse or promote products derived from
 *     this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 *
 *  Created on: Feb 2, 2014
 *      Author: Stefan Leutenegger (s.leutenegger@imperial.ac.uk)
 *    Modified: Zurich Eye
 *********************************************************************************/

/**
 * @file LocalParamizationAdditionalInterfaces.hpp
 * @brief Header file for the LocalParamizationAdditionalInterfaces class.
 * @author Stefan Leutenegger
 */

#pragma once

namespace ze {
namespace nlls {

/// \brief Provides some additional interfaces to ceres' LocalParamization
///        than are needed in the generic marginalisation okvisceres::MarginalizationError.
class LocalParamizationAdditionalInterfaces
{
 public:

  /// \brief Trivial destructor.
  virtual ~LocalParamizationAdditionalInterfaces() = default;

  /// \brief Computes the minimal difference between a variable x and a perturbed variable x_plus_delta
  /// @param[in] x Variable.
  /// @param[in] x_plus_delta Perturbed variable.
  /// @param[out] delta minimal difference.
  /// \return True on success.
  virtual bool Minus(const double* x, const double* x_plus_delta,
                     double* delta) const = 0;

  /// \brief Computes the Jacobian from minimal space to naively overparameterised space as used by ceres.
  /// @param[in] x Variable.
  /// @param[out] jacobian the Jacobian (dimension minDim x dim).
  /// \return True on success.
  virtual bool ComputeLiftJacobian(const double* x, double* jacobian) const = 0;

  /// \brief Verifies the correctness of an inplementation by means of numeric Jacobians.
  /// @param[in] x_raw Linearisation point of the variable.
  /// @param[in] purturbation_magnitude Magnitude of the delta used for numeric Jacobians.
  /// \return True on success.
  virtual bool verify(const double* x_raw, double purturbation_magnitude = 1.0e-6) const ;
};

}  // namespace nlls
}  // namespace ze

